Sustainable Utilization of Iron Ore Tailings as Sand Alternative in Cement Mortars

The growing pace of industrialization has significantly increased the annual production of iron, resulting in the generation of millions of tons of iron ore tailings (IOT). This study investigates the feasibility of utilizing IOT as a partial replacement for natural sand in cement mortar, aiming to reduce the depletion of natural resources and promote sustainable construction practices. Two types of IOT, Mega Hub Coarse (MC) and Mega Hub Fine (MF), were incorporated at replacement levels of 10%, 20%, 30%, and 40%, and keeping the water to cement ratio constant at 0.4. Workability and compressive strength at 7, 28, and 90 days were evaluated to assess the performance of the IOT mixes. Results revealed that increasing IOT content led to a reduction in flowability, more pronounced in MF mixes due to MF-IOT finer particles. However, compressive strengths improved at moderate replacement levels, peaking at 20% for MC and 30% for MF at 28 days of curing. Compressive strength at 28 days increased by 15.4% and 6.4% for MC-20% and MF-30%, relative to the control mix, respectively. The performance enhancement is attributed to the filler effect and enhanced bonding between surfaces as a result of IOT’s rough and angular texture. Overall, the findings demonstrate that IOT can serve as a viable and eco-friendly partial replacement for natural sand in mortar, helping to reduce the ongoing depletion of natural resources.